Sold by piece, sized by weight. Stones from different sizes may look similar in the pictures depending on the shape of each piece. Looks may be deceiving but weight isn't. For size reference a true to size cardboard bank card has been placed next to the stones. These pictures were taken both with the stones dry and sprayed with water.
 
Available while supplies last.
 
SM: 20-25g
MD: 30-35g
LG: 40-45g
XL: 50-60g